Abstract: The described invention comprises a method for detecting the onset or monitoring the recurrence of chronic graft versus host disease (cGVHD) in a transplantation patient. The method comprises isolating peripheral blood mononuclear cells (PBMCs) from the transplantation patient and analyzing the isolated PBMCs to detect a biomarker specific for a donor cell. The detection of the biomarker is indicative of the onset or recurrence of cGVHD in the transplantation patient.

Abstract: An optical variable attenuator includes first, second, third and fourth wedge shaped plates, each of said plates having two surfaces defined by an angle of convergence, the first and second plates being supported with two of said surfaces of said first and second plates being in spaced parallel alignment and with the angle of convergence of the two plates being in opposite directions, and the third and fourth plates being supported with two of said surfaces of said third and fourth plates being in spaced parallel alignment and with the angle of convergence of the third and fourth plates.